Was the holocaust truely unique, or do we say so to avoid the unfortunate truth that is really wasn’t. While the numbers were higher, the percentage of European Jews who died was similar to other events in out history (though the geographic range greater, a function of improved transportation). Similar acts of genocide have been quite common as well (consider the Middle Passage, the Irish hunger, and the genocide of the indigenous inhabitants of the Americas). While we like to say this time it was different because it was seen as a crime, had the Germans won the war it is unlikely (but not impossible) anyone wold have objected to the holocaust for many centuries. The period of rights and prosperity we have enjoyed in America the last 75 years is what it unique.
And looking at the rhetoric from the American left, we have reason to worry that matters will soon revert to the past, unpleasant, norm.